JP2003087861A - Sensor information collection system and sensor information collection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sensor information collection system by which a center can collect sensor information of a slave device even when the slave device cannot transmit the sensor information to the center via a master device in its own communication sub system, and to provide a sensor information collection method. SOLUTION: The sensor information collection system 10 of this invention includes a plurality of communication sub systems each configured to comprise one slave device 12 or more and a master device 13 to which the one slave device or more is wirelessly connected, and transmits the sensor information collected by the slave devices 12 to the center 15 via the master device 13. The system is characterized in that when the slave device 12A detects that the slave device 12A cannot transmit the sensor information to the center 15 via the master device 13A in its own communication sub system 14A, the slave device 12A transmits the sensor information to the center 15 via a master device 13B in other communication sub system 14B. Thus, even when the slave device 12A cannot transmit the sensor information via the master device 13A, the center 15 can collect the sensor information of the slave device 12A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensor information collecting system and a sensor information collecting method.

[0002]

2. Description of the Related Art Conventionally, as a technique in such a field, there is JP-A-8-212484. The sensor information collection system described in this publication wirelessly transmits sensor information collected by a specific low power radio device (slave device) from the slave device to a management room (center). Also, since the slave unit has a relay function, by setting the slave unit as a relay station,
It also enables data transmission over long distances. Therefore, by considering the slave unit functioning as a relay station as the master unit, the slave unit and the master unit wirelessly connected to this slave unit form a communication subsystem. Therefore, the sensor information collection system described above is considered to be composed of several communication subsystems.

[0003]

However, the above-mentioned conventional sensor information collecting system has the following problems. That is, since the child device and the parent device are installed outdoors, they are easily damaged. Then, due to a failure of the parent device, a child device in the same communication subsystem as the parent device, that is, a child device that relays the parent device to perform data transmission cannot send the sensor information to the center. was there.

The present invention has been made in order to solve the above-mentioned problems, and even when the slave unit cannot transmit the sensor information to the center via the master unit in its own communication subsystem, An object is to provide a sensor information collecting system and a sensor information collecting method capable of collecting sensor information in a center.

[0005]

A sensor information collecting system according to the present invention includes a communication sub-unit including one or a plurality of slave units and a master unit to which the one or a plurality of slave units are wirelessly connected. In a sensor information collection system that has multiple systems and transmits sensor information collected by the slave unit to the center via the master unit, the slave unit sends the sensor information to the center via the master unit in its own communication subsystem. When it is detected that transmission is not possible, the sensor information is transmitted to the center via the master device in another communication subsystem.

In this sensor information collecting system,
The sensor information of the child device is transmitted to the center via the parent device in its own communication subsystem to which the child device belongs. Then, if the child device cannot send sensor information to the center via the parent device in its own communication subsystem, for example, if the parent device is out of order or is in a busy state, the child device The machine transmits the sensor information to the center via the master machine in another communication subsystem. Therefore, even when the child device cannot transmit the sensor information to the center via the parent device in its communication subsystem, the sensor information of the child device is collected in the center.

Further, the master unit is supplied with the power supply voltage from the solar power supply, and when the slave unit detects that the power supply voltage of the master unit in the communication subsystem of itself is below a predetermined value, It is preferable to transmit the sensor information to the center via the master device in another communication subsystem. In this way, by adopting the solar power supply, it becomes possible to install the base unit without performing wiring work or the like. In addition, even when the power supply voltage of the master device is lowered to the extent that the master device cannot send the sensor information to the center by detecting that the power supply voltage of the master device is equal to or lower than the predetermined value, The sensor information of the child device in the same communication subsystem as the device is collected at the center.

Further, when the slave unit detects that the master unit in its own communication subsystem is communicating with another slave unit, the slave unit sends a sensor to the center via the master unit in the other communication subsystem. It is preferable to send the information. In this case, the child device can quickly transmit the sensor information to the center even when the parent device in its own communication subsystem is communicating with another child device.

Also, the slave unit transmits the sensor information to the master unit in another communication subsystem by relaying the other slave unit, and the master unit receiving the sensor information transmits the sensor information to the center. Preferably. In this case, for example,
Even if the cordless handset cannot establish a direct wireless connection with the parent device in the other communication subsystem, such as when the child device and the parent device in the other communication subsystem are in a long distance, By relaying, the sensor information of the slave unit is collected in the center.

Further, it is preferable that the slave unit is supplied with a power source voltage from a solar power source. In this case, the child device can be installed without performing wiring work.

A sensor information collecting method according to the present invention has a plurality of communication subsystems each including one or a plurality of slave units and a master unit to which the one or a plurality of slave units are wirelessly connected, In the sensor information collecting method of collecting sensor information by the sensor information collection system, which transmits the sensor information collected by the slave unit to the center via the master unit, the slave unit is configured to transmit the sensor information to the center via the master unit in its own communication subsystem. When it is detected that the sensor information cannot be transmitted to the center, a transmission step of transmitting the sensor information to the center via the master device in another communication subsystem is provided.

In this sensor information collecting method, the sensor information of the slave unit is transmitted to the center via the master unit in its own communication subsystem to which the slave unit belongs. And
For example, if the child device cannot send sensor information to the center via the parent device in its own communication subsystem, such as when the parent device is out of order or is busy, use the sending step. , The slave unit transmits the sensor information to the center via the master unit in another communication subsystem. Therefore, even when the child device cannot transmit the sensor information to the center via the parent device in its own subsystem, the sensor information of the child device is collected in the center.

Further, the master unit is supplied with the power supply voltage from the solar power supply, and when the slave unit detects that the power supply voltage of the master unit in the communication subsystem of itself is below a predetermined value, It is preferable to transmit the sensor information to the center via the master device in another communication subsystem. In this way, by adopting the solar power supply, it becomes possible to install the base unit without performing wiring work or the like. In addition, the slave unit detects whether the power supply voltage of the master unit is less than or equal to a predetermined value, and if it is less than or equal to the predetermined value, it is possible to transmit the sensor information to the center by the other master unit. Even when the power supply voltage drops, the sensor information of the slave unit in the same communication subsystem as the master unit is collected in the center.

When the slave unit detects that the master unit in its own communication subsystem is communicating with another slave unit, the slave unit sends a sensor to the center via the master unit in the other communication subsystem. It is preferable to send the information. In this case, the child device can quickly transmit the sensor information to the center even when the parent device in its own communication subsystem is communicating with another child device.

Further, the slave unit transmits the sensor information to the master unit in another communication subsystem by relaying the other slave unit, and the master unit receiving the sensor information transmits the sensor information to the center. Preferably. In this case, for example,
Even if the cordless handset cannot establish a direct wireless connection with the parent device in the other communication subsystem, such as when the child device and the parent device in the other communication subsystem are in a long distance, By relaying, the sensor information of the slave unit is collected in the center.

Further, it is preferable that the slave unit is supplied with a power source voltage from a solar power source. In this case, the child device can be installed without performing wiring work.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a sensor information collecting system and a sensor information collecting method according to the present invention will be described in detail below with reference to the accompanying drawings.

As shown in FIG. 1, the sensor information collecting system 10 according to the present embodiment comprises a plurality of cages 1 in a farm.
Each of the slaves 12 is provided with one slave 12 and two masters 13 surrounded by the slaves 12. The sensors described below are connected to each of the slaves 12, and the slaves 1
2 transmits the temperature and oxygen concentration (sensor information) of the cell 11 acquired from this sensor to the parent device 13 by specific low power radio. This specific low power radio is a radio performed in the 429 MHz band with specific low power (10 mW). In this way, the communication between the child device 12 and the parent device 13 by the specific low power radio facilitates the wiring work, and
Wireless low power communication and compact housing can be achieved.

When the base unit 13 receives the sensor information from the handset unit 12, the base unit 13 transmits the sensor information to the remote center 15 via a network such as a packet network for mobile phones. Then, by receiving the sensor information from each of the plurality of parent devices 13, the center 15 collects the sensor information from all the child devices 12. In this sensor information gathering system 10, Ikesu 11
8 slaves 12 installed in each of the squares are arranged in a substantially square shape, and the master 13 is located at the center of the square.
The communication subsystem 14 is configured by arranging the units. This communication subsystem 14 is installed in the farm.
2 are installed side by side, and the temperature and oxygen concentration of all the cages 11 in the farm are measured.

Next, the slave unit 12 constituting the sensor information collecting system 10 will be described. As shown in FIG. 2, the cordless handset 12 has an outer surface surrounded by a rectangular parallelepiped-shaped cordless handset casing 22 having a solar light receiving portion 21 on one surface. The antenna part 23 is installed. Also, the cordless handset 12 has a connection cable 24.
The temperature sensor 25 and the oxygen concentration sensor 26 are connected via the.

Here, two sensors attached to the child device 12, that is, a temperature sensor 25 and an oxygen concentration sensor 2 are provided.
6 will be described. The temperature sensor 25 measures the water temperature in the skein 11 and outputs an analog signal (4 m) according to the measured temperature.
A to 20 mA) is output. On the other hand, the oxygen concentration sensor 26
Measures the oxygen concentration in the cake 11 and outputs an analog signal (4 mA to 20 mA) according to the measured concentration.

Next, the system configuration of the slave unit 12 will be described with reference to FIG.

The handset 12 has handset solar light receiving portions 21, handset storage portions 31, and handset power supply parts 3 as functional components.
2, an antenna unit 23, a slave wireless transmission / reception unit 33, a slave wireless control unit 34, a sensor I / F unit 35, and a storage unit 36. The storage unit 36 stores a priority connection order database 37 that determines the order of the connection destinations (the base unit 13 and the handset 12) to which the handset 12 preferentially wirelessly connects. Specifically, for example, the highest priority connection destination is the master device 13
A (usually the master unit in its own communication subsystem) and the second priority connection destination is the slave unit 12B.
Hereinafter, each element will be described in detail.

The child device solar light receiving portion 21 is, for example, a solar panel that emits electricity when receiving sunlight, and is electrically connected to the child device power supply portion 32 via the child device power storage portion 31. The child device power storage unit 31 is, for example, an electric double layer capacitor, and is configured to be able to store the electric power supplied from the child device solar light receiving unit 21. Further, the electricity stored in the child machine power storage unit 31 is appropriately supplied to the child machine power supply unit 32. In this way, the slave unit 12 includes the solar light receiving unit 2
By adopting 1, it is possible to omit the troublesome installation work of the child device such as wiring work. In addition, by interposing the power storage unit 31 between the solar light receiving unit 21 and the power supply unit 32, the slave unit 12 can be driven even when power is not supplied from the solar light receiving unit 21 in cloudy weather or at night. ing. The slave power supply unit 32 also supplies power to the temperature sensor 25 and the oxygen concentration sensor 26 via the connection cable 24.

The antenna unit 23 is a transmission / reception antenna used for specific low power radio, and a slave radio transmission / reception unit 33.
In cooperation with the slave unit 12, the slave unit 12 and the other slave unit 12 and the master unit 1
3 and specific low power wireless communication can be performed. In addition, the slave unit radio control unit 34 is composed of, for example, a CPU and a memory, and is mainly for performing arithmetic processing, and can access the priority connection order database 37 stored in the storage unit 36. . The sensor I / F unit 35 converts sensor information of analog data transmitted from the temperature sensor 25 and the oxygen concentration sensor 26 via the connection cable 24 into sensor information of digital data.

Next, the master unit 13 which constitutes the sensor information collecting system 10 will be described.

As shown in FIG. 4, the parent machine 13 is fixed in the middle of a pillar 41 standing upright in the farm. Base unit 1
The unit 3 is covered with a base unit housing 43 having a base unit solar light receiving section 42 formed on one surface. Further, an upper antenna unit 44 for a mobile phone is provided on the upper part of the main unit housing 43, and a lower antenna unit 45 for specific low power radio is provided on the lower part of the main unit case 43.
Is provided.

Next, with reference to FIG. 5, the system configuration of the base unit 13 will be described.

The base unit 13 has, as functional components, a base unit solar light receiving section 42, a base unit power storage section 51, and a base unit power supply section 5.
2, upper antenna unit 44, lower antenna unit 45, mobile phone packet network control unit 53, TCP / IP conversion control unit 5
4, a parent device wireless control unit 55, and a parent device wireless transmission / reception unit 56. Hereinafter, each element will be described in detail.

The parent device solar light receiving portion 42 is, for example, a solar panel, like the child device solar light receiving portion 21, and is electrically connected to the parent device power source portion 52 via the parent device power storage portion 51. The base unit power storage unit 51 is, for example, an auxiliary battery,
The electric power supplied from the parent device solar light receiving section 42 can be stored. The electricity stored in the parent device power storage unit 51 is appropriately supplied to the parent device power supply unit 52. As described above, by adopting the solar light receiving section 42, the parent device 13 can omit troublesome parent device installation work such as wiring work. In addition, by providing the power storage unit 51 between the solar light receiving unit 42 and the power supply unit 52, the parent device 13 can operate as the child device 1
As in the case of No. 2, it can be driven even when power is not supplied from the solar light receiving unit 42.

The upper antenna section 44 is an antenna for packet communication of a mobile phone, and the upper antenna section 44, the mobile phone packet network control section 53, and the TCP / IP conversion control section 54 cooperate with each other to establish a master unit. 13 is a center 15 (see FIG.
(See) and packet communication via the Internet network. The base unit 13 includes a base unit wireless control unit 55 and a base unit wireless transmission / reception unit 56, and also includes a lower antenna unit 45 for specific low power wireless communication.
Can perform specific low-power wireless communication with the child device 12. Further, the parent device wireless control unit 55 is capable of detecting the value of the power supply voltage of the parent device power supply unit 52.

Next, the flow of sensor information in the sensor information collecting system 10 according to this embodiment will be described with reference to FIGS.

First, one child device 12A arranged in the cell 11 has a parent device 13 in its own communication subsystem 14A as indicated by arrows A1 and A2 in FIG.
A case where sensor information is transmitted to the center 15 via A will be described with reference to FIGS. 3 and 5.

When sensor information is transmitted from the temperature sensor 25 and the oxygen concentration sensor 26 to the slave unit 12A, the slave unit 12
The sensor I / F unit 35 of A converts the sensor information that is analog data into the sensor information that is digital data. The sensor information converted into digital data is sent to the handset wireless control unit 34 and subjected to arithmetic processing required for transmission. After that, the sensor information is selected by referring to the priority connection order database 37, and its own communication subsystem 1 is selected.
It is transmitted from the antenna unit 23 to the parent device 13A in 4A via the child device wireless transmission / reception unit 33 by the specific low power radio (FIG. 6).
Inside arrow A1).

The sensor information transmitted from the handset 12A is
The signal is received by the parent wireless transmission / reception unit 56 of the parent device 13A via the lower antenna unit 45. Then, the sensor information is sent to the master unit wireless control unit 55 and subjected to arithmetic processing required for transmission. After that, the sensor information is sent to the TCP / IP conversion control unit 5
4. By sequentially sending to the mobile phone packet network control unit 53, the processing necessary for packet communication via the Internet network is performed, and the upper antenna unit 44 to the center 15
To the mobile phone wireless (arrow A in FIG. 6).
2).

As described above, the sensor information collected by the slave unit 12A is transmitted to the center 15. And
The sensor information of the other handset 12 is also sent to the center 15 similarly to the sensor information of the handset 12A, so that the center 15
In addition, the sensor information of all the cages 11 in the farm, that is, the temperature and the oxygen concentration will be collected.

Next, one slave unit 12A arranged in the cage 11 is transferred to the center 15 via the master unit 13B in another communication subsystem 14B as shown by arrows B1 to B3 in FIG. A case where the sensor information is transmitted to will be described with reference to FIGS. 3 and 5. For convenience of explanation, the routes indicated by the arrows A1 and A2 are referred to as normal routes, and the routes indicated by the arrows B1 to B4 are referred to as detour routes.

In the detour route, as in the normal route,
From the temperature sensor 25 and the oxygen concentration sensor 26 to the slave unit 12A
When the sensor information is transmitted to the base unit 13A in the own communication subsystem 14A selected by referring to the priority connection order database 37, the sensor information is transmitted from the antenna unit 23 by the specific low power radio. (Arrow B1 in FIG. 7). Then, the information from the slave unit 12A is transmitted via the lower antenna unit 45 to the master unit wireless transmission / reception unit 56 of the master unit 13A.
Then, it is sent to the master unit wireless control section 55.

At this time, by the base unit wireless control unit 55,
The power supply voltage of the base unit power supply unit 52 is equal to or lower than a predetermined value, that is, the power supply voltage of the base unit power supply unit 52 is insufficient for transmitting sensor information from the base unit 13A to the center 15 by wireless for mobile phones. Is detected, the base unit wireless control unit 55
Indicates that transmission to the center 15 is impossible via the master unit wireless transmission / reception unit 56 and the lower antenna unit 45.
To notify. When the handset 12A receives this transmission failure notification, the handset wireless control unit 34 determines that the connection order is 2 based on the priority connection order database 37 stored in the storage unit 36.
The th master device 13B is determined.

It should be noted that the transmission failure notification from the master unit radio control section 55 is transmitted during communication with the slave units 12 other than the slave unit 12A (master unit 1).
3A busy state), communication trouble between the base unit 13A and the center 15 other than power shortage, the handset unit 12A cannot send sensor information to the center 15 via the base unit 13A in its own communication subsystem 14A. Depending on the case. Further, instead of transmitting sensor information from the child device 12A to the parent device 13A from the beginning, the child device 12A sends the sensor information to the parent device 13A.
First, the master device 13A receives the confirmation signal, and then transmits the transmission failure notification in response to the confirmation signal, whereby the communication data can be compressed and the information collection processing can be speeded up.

As a result, the sensor information is transmitted from the slave unit 12A to the master unit 13B via the slave unit wireless transmission / reception unit 33 and the antenna unit 23 (arrow B2 in FIG. 7). In this way, the master unit 1 that has received the sensor information from the slave unit 12A
3B transmits the sensor information to the center 15 by the wireless for mobile phones in the same manner as the base unit 13A on the normal route (arrow B3 in FIG. 7).

However, like the slave unit 12B shown in FIG.
If the distance between the slave 12B that transmits the sensor information and the master 13B in the other communication subsystem 14B adjacent to the communication subsystem 14A to which the slave 12B belongs is remote, the slave 12B is preferentially connected. The connection destination of the ranking database 37 may be the slave unit 12A. In this case, when the child device 12B receives the transmission failure notification from the parent device 13A after the child device 12B transmits the sensor information to the parent device 13A which is the highest priority connection destination (arrow C1), the sensor information of the child device 12B is received. Is transmitted to the secondary device 12A which is the second priority connection destination (arrow C
2). Then, the child device 12A transmits the sensor information of the child device 12B to the parent device 13A which is the highest priority connection destination of the child device 12A (arrow C3). Base unit 13 in the transmission disabled state
A then transmits a transmission failure notification to the child device 12A. It should be noted that the slave 12B transmits to the slave 12A the sensor information of the slave 12B together with the transmission-disabled notification from the master 13A, thereby omitting the data transmission (arrow C3) of the slave 12A to the master 13A. can do.

As a result, the slave unit 12A transmits the sensor information of the slave unit 12B to the master unit 13B in the adjacent other communication subsystem 14B, which is the second priority connection destination (arrow C4). Then, the parent device 13B transmits the sensor information to the center 15 by the wireless for mobile phones (arrow C).
5). In this way, the child device 12B that transmits the sensor information
And the distance from the parent device 13B in another communication subsystem 14B adjacent to the communication subsystem 14A to which the child device 12B belongs is remote, by relaying the other child device 12A, the parent device 13B The sensor information can be transmitted to the center via the.

When the relay function of the slave unit 12 is positively utilized, the normality of each slave unit is investigated by polling by the master unit 13, and the survey result is stored in the storage unit of each slave unit 12. By storing the data in 36 as a database, the relay of the child device 12 can be ensured. The relay of the slave unit 12 is performed by the antenna unit 23 and the slave unit wireless transmission / reception unit 33.
This is done in collaboration with (see Fig. 3).

As described above, the sensor information collected by the slave unit 12A is transmitted to the center 15 on the bypass route as well as the normal route. The sensor information of the other handset 12 is the same as the sensor information of the handset 12A.
By being sent to 5, the center 15 collects the sensor information of all the sacks 11 in the farm.

The present invention is not limited to the above embodiment, and various modifications can be made.

For example, the communication between the base unit and the center is not limited to the radio for mobile phones, but may be a wired line such as a general telephone line, ISDN, or a dedicated line. However, when the communication is wireless, the installation location of the parent device is not limited, so that it can be installed on the sea or in the mountains. Further, the sensor information is not limited to temperature and oxygen concentration, and may be any information that can be measured by a sensor such as atmospheric pressure or humidity. The parent device and the child device in the same communication subsystem may be wirelessly connected to each other via some child devices, instead of being directly wirelessly connected. Further, the sensor information from the sensor is not limited to analog data and may be digital data.

[0048]

The sensor information collecting system and the sensor information collecting method according to the present invention include one or a plurality of slave units, and
Alternatively, in a sensor information collecting system that has a plurality of communication subsystems including a master unit in which a plurality of slave units are wirelessly connected, and transmits the sensor information collected by the slave units to the center via the master unit, When the slave unit detects that it cannot send sensor information to the center via the master unit in its own communication subsystem, it sends the sensor information to the center via the master unit in another communication subsystem. Therefore, even if the child device cannot send sensor information to the center via the parent device in its own communication subsystem, it is possible to collect the sensor information of the child device in the center. is there.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a sensor information collection system according to an embodiment of the present invention.

FIG. 2 is a diagram showing a slave unit according to the embodiment of the present invention.

FIG. 3 is a system configuration diagram of the child device of FIG.

FIG. 4 is a diagram showing a master unit according to the embodiment of the present invention.

5 is a system configuration diagram of the parent device of FIG.

FIG. 6 is a diagram showing an example of a data flow of the sensor information collecting system according to the embodiment of the present invention.

FIG. 7 is a diagram showing an example of a data flow of the sensor information collecting system according to the embodiment of the present invention.

FIG. 8 is a diagram showing an example of a data flow of the sensor information collection system according to the embodiment of the present invention.

[Explanation of symbols]

10 ... Sensor information collecting system, 12, 12A, 12B
... Slave unit, 13, 13A, 13B ... Master unit, 14, 14A,
14B ... Communication subsystem, 15 ... Center, 25 ... Temperature sensor (sensor), 26 ... Oxygen concentration sensor (sensor).

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hironori Namioka             1-22 Nishi-Shinjuku, Shinjuku-ku, Tokyo Stocks             Company Hanex Central Research Institute (72) Inventor Kan Onishi             9-1, Tenjinmae, Takamatsu City, Kagawa Prefecture             Nuti Docomo Shikoku F term (reference) 2B104 CA01 CC00 CG00 EF09                 5K048 BA34 DA07 DB01 DC01 EB10                       HA01 HA02 HA03 HA39                 5K067 AA21 EE04 EE10 EE24 FF02                 5K101 KK12 LL01 LL11 MM07

Claims (10)

[Claims] 1. A plurality of communication subsystems each including one or a plurality of slave units and a master unit to which the one or a plurality of slave units are wirelessly connected, and sensor information collected by the slave units. In the sensor information collecting system for transmitting to the center via the master unit, when the slave unit detects that the sensor information cannot be transmitted to the center via the master unit in its own communication subsystem, A sensor information collecting system, characterized in that the sensor information is transmitted to the center via a master unit in another communication subsystem. 2. The master unit is supplied with a power supply voltage from a solar power supply, and the slave unit detects that the power supply voltage of the master unit in its own communication subsystem has dropped below a predetermined value. The sensor information collecting system according to claim 1, wherein the sensor information is transmitted to the center via the master unit in another communication subsystem when the sensor information is collected. 3. When the slave unit detects that the master unit in its own communication subsystem is in communication with another slave unit, the slave unit uses the master unit in another communication subsystem. The sensor information collecting system according to claim 1, wherein the sensor information is transmitted to the center. 4. The slave unit transmits the sensor information to the master unit in another communication subsystem by relaying the other slave unit, and the master unit that receives the sensor information transmits the sensor information to the master unit. The sensor information collection system according to claim 1, wherein the sensor information is transmitted to a center. 5. The sensor information collecting system according to claim 1, wherein the slave unit is supplied with a power supply voltage from a solar power supply. 6. Sensor information collected by the slave unit, which has a plurality of communication subsystems each including one or more slave units and a master unit to which the one or more slave units are wirelessly connected. In the sensor information collecting method of collecting sensor information in a sensor information collecting system for transmitting to the center via the master unit, the slave unit sends the sensor information to the center via the master unit in its own communication subsystem. The method for collecting sensor information, further comprising a transmitting step of transmitting the sensor information to the center via a master device in another communication subsystem when it is detected that the sensor information cannot be transmitted. 7. The power supply voltage is supplied to the master unit from a solar power supply, and the slave unit detects that the power supply voltage of the master unit in its own communication subsystem has dropped below a predetermined value. The sensor information collecting method according to claim 6, wherein the sensor information is transmitted to the center via the master device in another communication subsystem. 8. When the slave unit detects that the master unit in its own communication subsystem is in communication with another slave unit, the slave unit uses the master unit in another communication subsystem through the master unit. The sensor information collecting method according to claim 6, further comprising transmitting the sensor information to the center. 9. The slave unit transmits the sensor information to the master unit in another communication subsystem by relaying the other slave unit, and the master unit that receives the sensor information transmits the sensor information to the master unit. The sensor information collecting method according to claim 6, wherein the sensor information is transmitted to a center. 10. The sensor information collecting method according to claim 6, wherein the slave unit is supplied with a power supply voltage from a solar power supply.